Aye-Aye Lemur Enrichment Feeder

Aye Aye Lemur

Image: Duke Lemur Center

Background

Aye-ayes are nocturnal lemurs native to Madagascar, and utilize a bioacoustic feedback system for foraging and feeding. The Duke Lemur Center houses nine of only 24 captive aye-ayes in the United States. In compliance with U.S. Department of Agriculture regulations, primates held in captivity must be provided enrichment for their psychological well-being. Stimulation prevents the development of stereotypies, depression, lack of appetite, etc. The design challenge for this project was to create a novel enrichment feeding device to be used for aye-aye lemurs housed at the Duke Lemur Center, to improve upon existing methods by providing for a more realistic feeding experience for the animals. This work was done over four months as part of Duke's Engineering Design and Communication course.

Role

Research, engineering design, fabrication, testing, client relations

Client

Duke University Lemur Center

Timeline

Aug 2018 - Dec 2018

Collaborators

Malvika Jain, Will Garcia, Ethan Austin, Jenny Liang

wood block

Wooden blocks for lemur food delivery

Problem

Since a significant percentage of an aye-aye’s diet consists of insect larvae that dwell inside dead or living trees, aye-ayes have developed long, skeletal fingers that they use to tap upon branch surfaces. Then they use their ears to search for characteristic echoing sounds which may indicate the location of an insect tunnel. After tearing off outer bark, aye-ayes utilize their fingers to hook their prey.

The existing methods used by the Duke Lemur Center included hollow wood blocks filled with mealworms. This was a time-consuming process that required Lemur Center techs to drill holes into wooden blocks, fill them with food, and then seal the ends with cork. It was also wasteful since each block could only be used once.

Aye-aye enclosure

Challenges and Constraints

Material: Aye-ayes are able to gnaw through materials including bamboo, wood, and plastics. This makes designing for non-chewable components quite difficult due to limited material selection.

Workflow: Our new device must fit into/improve the existing workflow at the Duke Lemur Center.

Infrastructure: Ideally, our device would be compatible with existing mounting points from inside the animal enclosure.

Design Iteration

As an engineering design team, we were able to design and prototype an enrichment feeder for aye-ayes in the Duke Lemur Center that is cheaper and more stimulating than the current device. Inspired by hollow chambers inside trees, our design solution is a metal puzzle feeder that has a system of tunnels that can be rearranged, thus creating variability and increasing enrichment. This also mimics aye-aye tap-foraging behavior in the wild, while still allowing for integration with the lemur center's existing infrastructure and workflow (including mounting, sanitation).

Low-fidelity prototypes were created first, to establish a proof of concept. These facilitated communication of our idea with our client and served as the foundation for further development in CAD. Further prototypes were created using 3D printed parts, with the final design intended to be machined.

Lemur Feeder

Poster

© 2021 Alex Xu

Updated 9/2021